Toner processes

Abstract

A toner process comprising heating a mixture of a latex and a colorant, which heating is accomplished below about the glass transition temperature, Tg, of polymer contained in the latex; cooling; and subsequently adding a methacrylate polymer solution; adjusting the pH of the mixture resulting to permit the methacrylate polymer to precipitate on said mixture of latex and said colorant; and wherein resulting product is heated above about the glass transition temperature, Tg, of said latex polymer.

1. A toner process comprising heating a mixture of a latex and a colorant, which heating is accomplished below about the glass transition temperature, Tg, of polymer contained in the latex; cooling; and subsequently adding a methacrylate polymer solution; adjusting the pH of the mixture resulting to permit the methacrylate polymer to precipitate on said mixture of latex and said colorant. 
     
     
       2. A process in accordance with  claim 1  wherein said latex contains a polyester polymer, and wherein the pH is adjusted to about 7. 
     
     
       3. A process in accordance with  claim 2  wherein said latex contains a sulfonated polyester, and wherein the pH is adjusted to about 7. 
     
     
       4. A process in accordance with  claim 1  wherein said latex polymer is a polyester of the formula 
                 
 
       wherein Y is an alkali metal, X is a glycol, and n and m each represent the number of segments. 
     
     
       5. A process in accordance with  claim 4  wherein said polyester resin is poly(1,2-propylene-sodio 5-sulfoisophthalate). 
     
     
       6. A process in accordance with  claim 4  wherein said polyester resin is polyneopentylene-sodio 5-sulfoisophthalate polyester. 
     
     
       7. A process in accordance with  claim 4  wherein said alkali metal is sodium, or potassium. 
     
     
       8. A process in accordance with  claim 4  wherein said glycol is an alkylene glycol. 
     
     
       9. A process in accordance with  claim 8  wherein said glycol is an aliphatic glycol of neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, propanediol, 1,2-propanediol, diethylene glycol, dipropylene glycol, or optionally mixtures thereof. 
     
     
       10. A process in accordance with  claim 4  wherein said m and said n each represent a number of from about 10 to about 30. 
     
     
       11. A process in accordance with  claim 4  wherein the weight average molecular weight (M w ) of said polyester is from about 2,000 grams per mole to about 100,000 grams per mole, the number average molecular weight (M n ) is from about 1,000 grams per mole to about 50,000 grams per mole, and the polydispersity thereof is from about 2 to about 18 as measured by gel permeation chromatography. 
     
     
       12. A process in accordance with  claim 1  wherein said methacrylate is a butylmethacrylate-(2-dimethylaminoethyl) methacrylate/methylmethacrylate copolymer. 
     
     
       13. A process in accordance with  claim 12  wherein said polymer ratio of said segments is 1:2:1. 
     
     
       14. A process in accordance with  claim 13  wherein said polymer ratio is about 25 percent:50 percent:25 percent; about 33 percent:33 percent:33 percent; about 0 percent:25 percent:75 percent; or about 0 percent:0 percent:100 percent. 
     
     
       15. A process in accordance with  claim 1  wherein said methacrylate is a butylmethacrylate-(2-dimethylaminoethyl)methacrylate-methylmethacrylate copolymer (1:2:1) containing (2-dimethylaminoethyl) methacrylate, butyl methacrylate and methyl methacrylate with a mean molecular weight, M w  of from about 125,000 to about 175,000. 
     
     
       16. A process in accordance with  claim 1  wherein said methacrylate is present in an amount of from about 1 to about 10 percent by weight. 
     
     
       17. A process in accordance with  claim 1  wherein said methacrylate is present in an amount of from about 3 to about 7 percent by weight. 
     
     
       18. A process in accordance with  claim 1  wherein said methacrylate is a butylmethacrylate-(dimethylaminoethyl methacrylate/methylmethacrylate copolymer present in an amount of from about 1 to about 10 percent by weight. 
     
     
       19. A process in accordance with  claim 1  wherein said methacrylate is a butylmethacrylate-(dimethylaminoethyl) methacrylate/methylmethacrylate copolymer present in an amount of from about 3 to about 7 percent by weight. 
     
     
       20. A process in accordance with  claim 1  wherein said pH is from about 8 to about 12. 
     
     
       21. A process in accordance with  claim 1  wherein said pH above 7 is from about 10 to about 11. 
     
     
       22. A process in accordance with  claim 1  wherein the pH of the resulting mixture after heating is from about 2 to about 5, and which pH is increased to from about 9 to about 12 subsequent to the addition of said methacrylate. 
     
     
       23. A process in accordance with  claim 22  wherein the pH is increased by the addition of a base. 
     
     
       24. A process in accordance with  claim 23  wherein the base is an alkali metal hydroxide. 
     
     
       25. A process in accordance with  claim 23  wherein the base is sodium hydroxide. 
     
     
       26. A process in accordance with  claim 1  wherein the pH of the resulting mixture after heating is from about 2 to about 4 and which pH is increased to from about 10 to about 12 subsequent to the addition of said methacrylate. 
     
     
       27. A process in accordance with  claim 1  further including adding a wax to said latex and said colorant mixture. 
     
     
       28. A process in accordance with  claim 27  wherein said wax a polypropylene, a polyethylene, or mixtures thereof. 
     
     
       29. A process in accordance with  claim 27  wherein said wax is a polyethylene. 
     
     
       30. A process in accordance with  claim 27  wherein said wax possesses a low weight average molecular weight M w  of from about 1,000 to about 20,000. 
     
     
       31. A process in accordance with  claim 1  wherein there is further included a coagulant. 
     
     
       32. A process in accordance with  claim 1  wherein there is further included a coagulant of zinc acetate. 
     
     
       33. A process in accordance with  claim 1  wherein said heating is from about 35° C. to about 55° C. 
     
     
       34. A process in accordance with  claim 1  further including a second heating above the latex resin Tg subsequent to said addition of said methacrylate polymer. 
     
     
       35. A process in accordance with  claim 34  wherein said heating is from about 70° C. to about 95° C. and wherein coalescence results for said latex resin, said colorant and said methacrylate, and which methacrylate is present on the surface of said resulting toner. 
     
     
       36. A process in accordance with  claim 35  wherein said polymer is present in an amount of from about 80 to about 98 percent by weight, and said colorant is present in an amount of from about 2 to about 20 percent by weight of the toner. 
     
     
       37. A process in accordance with  claim 1  wherein the colorant is a pigment. 
     
     
       38. A process in accordance with  claim 1  wherein said latex polymer is selected from the group consisting of poly(styrene-butadiene), poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene), poly(butyl acrylate-butadiene), poly(styrene-isoprene), poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene), poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene), poly(butyl acrylate-isoprene); poly(styrene-propyl acrylate), poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylic acid), poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid), poly(styrene-butyl acrylate-acrylononitrile), and poly(styrene-butyl acrylate-acrylononitrile-acrylic acid). 
     
     
       39. A process in accordance with  claim 1  wherein the colorant is carbon black, cyan, yellow, magenta, or mixtures thereof, and the toner resulting is from about 2 to about 25 microns in volume average diameter, and wherein there is optionally added to the surface of the formed toner metal salts, metal salts of fatty acids, silicas, metal oxides, or mixtures thereof, each in an amount of from about 0.1 to about 10 percent by weight of the obtained toner. 
     
     
       40. A toner process comprising heating a mixture of a latex and a colorant, which heating is accomplished below about the glass transition temperature, Tg, of polymer contained in the latex; cooling; and subsequently adding a methacrylate polymer solution; adjusting the pH of the mixture resulting to permit the methacrylate polymer to precipitate on said mixture of latex and said colorant; and wherein resulting product is heated above about the glass transition temperature, Tg, of said latex polymer. 
     
     
       41. A toner process comprising heating a mixture of a latex and a colorant, which heating is accomplished below about the glass transition temperature, Tg, of polymer contained in the latex; cooling; and subsequently adding a methacrylate polymer solution; adjusting the pH of the mixture resulting to permit said methacrylate to form on said mixture of said latex and said colorant; and wherein resulting product is heated above about the glass transition temperature, Tg, of said latex polymer.